Removeable Storage

Removable Storage: From Paper Tape to Thumb Drives and Beyond A Presentation by Joel May

Removable Storage
Paper Tape
Punched Cards
Cassette Tapes
8” Floppy Disks
5¼” Floppy Disks
3½” Floppy Disks
Portable Hard Drives
Zip Drives
Optical Storage (CD, DVD, etc.)
Flash Memory
USB Thumb Drives

Removable Storage
Paper Tape (1725 – 1970s)
Punched Cards
Cassette Tapes
8” Floppy Disks
5¼” Floppy Disks
3½” Floppy Disks
Zip Drives
Flash Memory
USB Thumb Drives

Paper Tape

Paper Tape
Invented in 1725 by Basile Bouchon as a medium to hold information used by looms when weaving complex-patterned fabrics
Widely used during much of the twentieth century for teletypewriter communication

Paper Tape
When the first minicomputers were released, most manufacturers turned to teletypewriters as a low-cost solution for keyboard input and printer output
As a side effect punched tape became a popular medium for low cost storage
In the ’60s and ’70s it was common to find a selection of tapes containing useful programs in most minicomputer installations.

Paper Tape
Slow (75 WPM)
Awkward (Difficult to recoil the tape issuing from the reader)
Some applications used fan-fold tape which was an improvement
Fragile (Tape tore easily and was difficult to mend)
Difficulties

Removable Storage
Punched Cards (1890 – Present)
Cassette Tapes
8” Floppy Disks
5¼” Floppy Disks
3½” Floppy Disks
Zip Drives
Flash Memory
USB Thumb Drives

Punched Cards

Punched Cards
Herman Hollerith developed punched card data processing technology for the 1890 US census
IBM manufactured and marketed a variety of machines for creating, sorting, and tabulating punched cards, even after expanding into computers in the late 1950s

Punched Cards
Punched cards are still in limited use gathering input data for computers. Recall the “hanging chad” debacle in Florida during the 2000 presidential election
However they were never (to my knowledge) used as removable storage for microcomputers

Removable Storage
Cassette Tapes (1973 – 1983)
8” Floppy Disks
5¼” Floppy Disks
3½” Floppy Disks
Zip Drives
Flash Memory
USB Thumb Drives

Cassette Tape

Cassette Tape
Most microcomputers of the late 1970s and early 1980s used cassette tape for storage of both program software and data
Tapes could be read or written at a speed of from 500 to 1000 bps
A 90-minute cassette had a total capacity of approximately 330 KB per side

Cassette Tape
Users had to fast forward or rewind the tape to the correct spot and then “read” the contents of the tape into the computer’s RAM
The first version of the IBM PC of 1981 had a cassette port and a command in its ROM BASIC programming language to use it

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks
3½” Floppy Disks
Zip Drives
Flash Memory
USB Thumb Drives

8″ Floppy Disk

8″ Floppy Disk
In 1967, IBM wanted a way, faster and lighter than tape reels, to load microcode into their customers’ System/370 mainframes
Their solution was a read-only 8” diameter plastic disk with a coating of magnetic material that had a storage capacity of 80 KB and cost only $5
In later versions, the storage capacity was increased to 250 KB

8″ Floppy Disk
Because they featured random access to the stored data, they were considered “high speed” compared to cassette tapes
But the drives were expensive, typically costing more than the computer to which they were attached
The first microcomputer operating system, CP/M, originally shipped on 8″ disks

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks
Zip Drives
Flash Memory
USB Thumb Drives

5¼″ Floppy Disk

5¼″ Floppy Disk
Northstar introduced the 5¼” floppy in 1977. The originals were hard sectored diskettes that had ten holes in them marking the beginning of each of the ten sectors.
The storage capacity was only 70 kilobytes. A double density controller released the following year provided 140K.

5¼″ Floppy Disk
Beginning in 1979, the 5¼″ format now, thanks to Maxell, available in a soft sectored version, quickly displaced the 8″ for most applications and began to make serious incursions into the domination of cassette tapes

5¼″ Floppy Disk
Like the 8″ Floppy, the 5¼″ version consisted of a thin metallic-coated plastic disk encased in a felt-lined paper sleeve

5¼″ Floppy Disk Plastic Disk Paper Sleeve

5¼″ Floppy Disk
The paper sleeve had an oval cutout through which the drive head could access the information stored on the plastic disk

5¼″ Floppy Disk Oval Cutout

5¼″ Floppy Disk
Because of their construction, they were very fragile, easily bent or creased
They were also extremely sensitive to heat and magnetic fields
Placing one on top of a computer or on the dashboard of a car on a sunny day could cause major data loss

5¼″ Floppy Disk
On the right side there was a notch called the “write-enable slot”

5¼″ Floppy Disk Write-Enable Slot

5¼″ Floppy Disk
To make the disk read-only, one had to paste a small piece of paper over the notch

5¼″ Floppy Disk
These early drives read only one side of the disk, leading to the popular budget approach of cutting a second write-enable slot and index hole on the opposite edge of the carrier envelope and flipping it over to use the other side for additional storage (thus, the "flippy disk")

5¼″ Floppy Disk
When first introduced, 5¼″ disks had a maximum storage capacity of 180 KB
Tandon introduced a double-sided drive in 1980, doubling the capacity to 360 KB
In 1982 a new "double density" format increased it again, to 720 KB

5¼″ Floppy Disk
Finally, in 1984, a “high density” version was introduced with a storage capacity of 1200 KB (1.2 MB)
Since the IBM AT personal computer, also introduced that year, had a hard drive that stored a maximum of 10 to 20 MB, the capacity of the high density 5¼″ floppy was considered quite large for its price

5¼″ Floppy Disk
For most of the 1980s the 5¼″ floppy drive was the primary storage device for microcomputers.
Since many of these micros had no hard drive, the OS was usually booted from one floppy disk, which was then removed and replaced by another one containing the application.
Some machines using two disk drives (typically “A” and “B”) allowed the user to leave the OS disk in place and simply change the application disks as needed

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks (1983 – 2005)
Zip Drives
Flash Memory
USB Thumb Drives

3½″ Floppy Disk

3½″ Floppy Disk
By the end of the 1980s, the 5¼″ disks had been superseded by the 3½″ disks
The latter had a number of advantages over the older format, including a small form factor and a rigid case with a slideable write protect catch

3½″ Floppy Disk Rigid Case Slideable Write-Protect catch Metal plate slides aside for access to the plastic disk inside

3½″ Floppy Disk
The standard version was released by Sony in 1983 with a capacity of 360 KB (the same capacity as the 5¼″ disks of the time)
In 1986, a 720 KB version was introduced
A newer "high-density" format, displaying an "HD" on the disks themselves and storing 1440 KB (1.44 MB) of data, was introduced in 1987

3½″ Floppy Disk
By 1988, they were outselling the 5¼″ version
The 1.44 MB High Density floppy drive soon became universal on virtually all PC and Macintosh hardware and remained so for 16 years - until 2004
In 2004, Dell became the first major personal computer supplier to make the 3½″ floppy drive an optional extra

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks (1983 – 2005)
Portable Hard Drives (1991 – Present)
Zip Drives
Optical Storage
Flash Memory
USB Thumb Drives

The First Portable Hard Drive (in the act of being transported) 1956: The hard drive for the IBM 305 RAMAC weighed more than a ton
Capacity 5MB –
Cost $10,000,000 / MB

No different in basic technology from ordinary hard drives, just easier to move around
Capacities range from 20GB to 1TB
Prices range from $15 to $150
Typically powered by the USB port on the host computer

The most common are those based on 1” Microdrives
They aren't much larger than the drive they contain, and often have retractable USB plugs

They are meant to have the same practicality and ease of use of flash drives (discussed later)
But they are still based on an actual (albeit micro-sized) hard disk with moving heads and spinning platters, so they are much less tolerant of abuse

Their principal advantage is that they are transportable, plugging into any computer via a USB port
Their principal disadvantages are their fragility and the fact that they are noticeably slower than an internal hard drive

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks (1983 – 2005)
Zip Drives (1994 – 1998)
Flash Memory
USB Thumb Drives

Iomega Zip Drive

Beyond Floppies
The Zip drive was a large-capacity removable disk storage system, introduced by Iomega in late 1994
Originally it had a capacity of 100 MB, but later versions increased this to 250 MB and then 750 MB
The drive was initially sold for just under $200 with one cartridge included, and additional 100 MB cartridges sold for $20

Beyond Floppies
There were many competitors:
Jaz drive
Bernoulli Box
Ditto drive
LS-120 drive
EZ 135 Drive
Orb Drive
All very similar in construction, cost and capacity

Beyond Floppies
They sold well at first because they were seen a relatively inexpensive substitutes for the hard drives of the day
But by 1998 these disks had a relatively high cost per megabyte compared to the falling costs of both hard drives and optical storage media (CD-RW and DVD±RW)

Beyond Floppies
There was also the problem of:
The Click of Death
Without warning, the Zip drive would sound a loud click and both drive and data would be lost forever.

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks (1983 – 2005)
Zip Drives (1994 – 1998)
Optical Storage (1995 – Present)
Flash Memory
USB Thumb Drives

Optical Storage Devices

Optical Storage
All the storage devices we’ve talked about so far, since the punched cards, are Magnetic storage devices
That is, they store the information on a metallic surface in the form of magnetic “dots”

Optical Storage
On Optical drives, when data are recorded, a laser burns tiny “pits” in a reflective material on the disk
The data are read by detecting variations in the intensity of the reflected light from the media surface

Optical Storage
Optical recording systems potentially have much greater reliability
There is a much larger distance between the read/write element and the moving media and therefore no wear associated with repeated use of the optical systems

Optical Storage
The main disadvantages of optical storage when compared to magnetic is slower random data access.
This partially comes from the design of the relatively large and heavy optical heads

Optical Storage
Forms of Optical Storage
CD-R, CD-RW (Introduced 1995)
DVD-RAM,
DVD-R, DVD-RW, (Introduced 1998-2001)
DVD+R, DVD+RW
- Blu-ray and HD DVD (Introduced 2003)

CD-R (Compact Disk – Read Only)
First introduced in 1997, CD-Rs have a capacity of 645 to 700MB
They can be written to only once
Used primarily for music and video
Also sometimes used to transfer files between users

CD-RW (Compact Disk-Rewritable)
Also introduced in 1997, CD-RWs have the same capacity as CDRs (645 to 700 MB) but they can be written to approximately 1,000 times
They have a “shelf life” of 3 to 5 years
Despite their relatively low cost, they have not been adopted for wide-spread use as removable storage devices

CD-RW (Compact Disk-Rewritable)
The process of transferring data to them is much slower than to other storage devices
It requires specialized software
CD-RW disks need to be re-formatted either entirely or "on the fly" before recording new data
They are most useful for temporary short or mid-term backups

DVD (Digital Versatile/Video Disk)
DVD-RAM:
Introduced in 1998
Single-sided capacity 4.7 GB
Double-sided capacity 9.4 GB
Can be accessed just like a hard or floppy disk without any special software

DVD-RAM:
Long life - without physical damage, data is retained for 30 years minimum.
Can be rewritten over 100,000 times (DVD±RW can be rewritten approximately 1,000 times)
DVD-RAM media is more expensive than other DVD types (~$9 per disk)
DVD-RAM writing is slower than DVD+RW and DVD-RW
Excellent for use as a long-term backup medium

DVD-RW and DVD+RW:
Mostly Tweedledum and Tweedledee
DVD-RW introduced by Pioneer in 1999
DVD+RW introduced by Phillips in 2001
Both have a capacity of 4.7 GB and record at comparable speeds
Both have a estimated life of 10 years or 1000 writes

DVD-RW and DVD+RW:
DVD+RW supports random write access, which means that data can be added and removed without erasing the whole disc and starting over
Conversely, DVD-RW is more like CD-RW: to change data, one must erase the whole disc and start over again

DVD-RW and DVD+RW:
Originally the two formats were competitive with one another
But by 2002 Sony introduced a DVD±RW drive that could read or write in both formats
There are still some compatibility problems with older home DVD players

DVD-RW and DVD+RW:
In May 2004, Sony introduced a dual-layer DVD-RW with a capacity of 9 GB

Blu-ray and HD DVD
Introduced early 2003
Used primarily as entertainment media
Competitive situation similar to VHS vs Betamax
Blu-ray backed by Sony, Panasonic, Samsung, Dell, HP, and Philips
HD DVD backed by Toshiba, NEC, Microsoft, and LG

Blu-ray
Capacity of 50 GB
Disks and players were more expensive
Players $900-$1200
Disks $25-$35
Got a head start of about 6 months
HD DVD
Capacity of 30 GB
Less costly
Players $400-$600
Disks $15-$25
Had a more recognizable name

Blu-ray Won!
In February, 2008, Toshiba abandoned the format, announcing it would no longer develop or manufacture HD DVD players or drives and major content manufacturers and key retailers began withdrawing their support for the format
Today a Blu-ray player can be bought for anywhere from $75 to $200
Blu-ray 3D players go for $200 to $400

Now let’s turn back to Magnetic memory...

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks (1983 – 2005)
Zip Drives (1994 – 1998)
Flash Memory (1995 – Present)
USB Thumb Drives

Flash Memory
Flash memory is a form of non-volatile computer memory that can be electrically erased and reprogrammed
Flash memory costs far less than other forms of non-volatile memory and therefore has become the dominant technology wherever a significant amount of non-volatile, solid-state storage is needed

Flash Memory
Flash memory offers faster read access times and better kinetic shock resistance than hard disks
Another allure of flash memory is that when packaged in a “memory card” it is nearly indestructible by ordinary physical means, being able to withstand intense pressure and boiling water

Flash Memory
Examples of applications include digital audio players, digital cameras, GPS devices and cell phones.
There are many manufacturers of flash memory devices and almost as many shapes, sizes and capacities

Flash Memory Just a few examples:

Flash Memory
Flash memory can be accessed by the device in which it is contained
Storing pictures on a digital camera
Playing music on a MP3 player or iPod
Displaying maps in a GPS device
Playing saved messages or downloading ringtones on a cell phone

Flash Memory
Flash memory can also be accessed by a desktop or laptop computer or by a printer
Directly, by connecting the device containing the flash memory to a computer or printer using a USB connection
Or indirectly, via...

Flash Memory A card reader built into a desktop computer

Flash Memory A card reader built into a photo printer

Flash Memory A free-standing card reader that connects via a USB cable

Flash Memory But the really important thing to remember is All Flash Memory Devices are the Same Inside Whether they be:
MP3 Players
Compact Flash Cards
Memory Sticks
Secure Digital Cards
Smart Media Cards
or whatever

Flash Memory
Among other things, this means you can:
Take a bunch of pictures with your digital camera
Remove the memory card from your camera and put it in your pocket
Come over to my house
Plug the memory card into my computer
Show me the pictures

Flash Memory
Among other things, this means you can:
Show up at my house with your mp3 player
See a new program on my computer of which you’d like to have a copy
Copy the installation software from my computer to your mp3 player
Return home and copy the software from your mp3 player to your hard drive
Install it on your computer

Flash Memory
Flash memory is also used in USB thumb drives (also called flash drives, jump drives, pocket drives, handy drives, stick drives, etc), which are used for general storage and transfer of data between computers.

Removable Storage
8” Floppy Disks (1967 – 1980)
5¼” Floppy Disks (1977 – 1989)
3½” Floppy Disks (1983 – 2005)
Zip Drives (1994 – 1998)
Flash Memory (1995 – Present)
USB Thumb Drives (2000 – Present)

USB Thumb Drives

USB Thumb Drives
USB thumb drives are compact and easy-to-use devices that are similar in function to a computer hard drive
USB thumb drives slip into your pocket, on a lanyard around your neck or on a keychain for ultimate portable storage

USB Thumb Drives
A thumb drive consists of a small printed circuit board encased in a robust plastic or metal casing
Only the USB connector protrudes from this protection, and is usually retractable or covered by a removable cap
Thumb drives use a standard type-A USB connection allowing them to be connected directly to a port of a personal computer

USB Thumb Drives
To access the data stored in a thumb drive, the drive must be connected to the computer's USB port
Thumb drives are active only when powered by a USB computer connection, and require no other external power source or battery power source
They are powered using the limited supply afforded by the USB connection.

USB Thumb Drives
Currently, memory capacity ranges from 4GB up to 256GB, limited only by flash memory densities
USB Thumb Drives are relatively inexpensive although cost per megabyte increases rapidly at higher capacities due to the expensive components

USB Thumb Drives
Based on a recent price check, thumb drives were available in retail stores and online at $5 for 4GB, $11 for 16GB, and $65 for 64GB (or about $1 per GB)
A 128GB drive could be had for about $230 and a 256GB version was priced around $700

They can be used for transporting personal files (just like floppies, but a lot more capacious)
Data
Music
Pictures
Video
Some Things You can Do With a USB Thumb Drive

Trek With Books, Not a Backache
load up your thumb drive with some of the thousands of free e-books (in text format) available from Project Gutenberg (www.gutenberg.org)
Tunes on Wheels
- A thumb drive is great for carting music
around, and if you're in your car, with the
right hardware you can play the tunes right
from it too—no software required

Run preinstalled programs from a specially formatted thumb drive
PortableApps
Download and install on any thumb drive from www.portableapps.com (no preformatting required)
Requires ~370MB of space on the thumb drive (plus space for additional programs and document storage)

PortableApps AntiVirus Package Browser Instant Messaging Microsoft Office Substitute Math Game Calendar Email

With PortableApps, you can:
Plug your UTD into the USB port of any computer anywhere – a friend’s house, an Internet Café, a hotel business center, an office – anywhere, and see your own familiar desktop, programs, and data
Run Portable Firefox to surf the Web or Portable Thunderbird to pick up email; put the final touches on your document or slide show presentation with Writer or Impress; play your favorite music or watch videos

Some Things You can Do With a USB Thumb Drive Then: Remove the UTD at the end of the session and no record of your session or anything else personal remains on the host computer

Removable Storage: What Does the Future Hold?
Today's storage devices are based on magnetic or optical technology. They may be sufficient for today's need but are fast hurtling toward obsolescence as the power of the silicon processors increases.
To meet this need for faster and more efficient storage devices, there are many promising products on the horizon.

Holographic Memory
An advanced form of optical storage (like CD and DVD)
It is three dimensional, instead of two dimensional, and offers much better data density and transfer speed
A holographic disk would be the shape and size of a DVD but have a capacity 27 times greater. This would translate to about 1 terabyte of data per disk. In addition, the holographic storage device would have a data transfer rate 25 times greater than today's DVDs
It is estimated that holographic storage devices may become commonplace in another four or five years or so

Molecular Memory
Individual molecules and nanowires are used to create large arrays of memory bits. Each molecule acts like a switch that can be either in the off or on state, thus representing digital data
With this technology, up to 50 times more data (65 GB/sq in) can be crammed into the same storage space as today's magnetic storage devices such as hard disks
Molecular memory is still in the realm of research and practical applications are still a decade or so away

And More…
Carbon Nanoballs
Interest is growing in the use of metallofullerenes - carbon "cages" with embedded metallic compounds - as materials for miniature data storage devices
Researchers at The Swiss Federal Laboratories for Materials Science and Technology have discovered that metallofullerenes are capable of forming ordered supramolecular structures with different orientations
By specifically manipulating these orientations it might be possible to store and subsequently read out information

And More…
Bacteria
Trust your data with tiny bugs? Artificial DNA with encoded information can be added to the genome of common bacteria, thus preserving the data
According to researchers, up to 100 bits of data can be attached to each organism
Scientists have successfully encoded and attached the phrase "e=mc2 1905" to the DNA of bacillus subtilis, a common soil bacteria

Summary
We are reaching the point where we can finally fulfill the real promise of the digital age:
Complete freedom and mobility

The End Removable Storage: From Paper Tape to Thumb Drives and Beyond This presentation is available for viewing at www.joelmay.org/presentations

Removeable Storage

by Joel May on Jun 30, 2011

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Removeable Storage — Presentation Transcript